One obvious geopolitical legacy of the PyeongChang Olympics is that it provided a momentum for improvement of inter-Korean relations that had been stalled for years due to the North’s nuclear and missile crisis.

There are some downsides to the latest thaw, including objections within the South and a skeptical view of the US, which still focuses more on sanctions and pressure than on dialogue. But the two Koreas need to continue their hard-won rapprochement.

Indeed, the PyeongChang Olympics heightened the reconciliatory mood between the two Koreas to the degree that some called it the “Peace Olympics.” It certainly eased tension which was so high as to stoke fears of the South being swept into a war between the US and the North.

The South Korean government of President Moon Jae-in took the initiative in the peace efforts. It persuaded the US to delay the joint military exercises until after the Olympics and obtained exceptions to US-led sanctions to allow the visit of senior North Korean officials and use of aircraft and the ferry.

North Korea responded by -- in addition to sending athletes, performers and a cheering squad -- dispatching high-powered delegations to both the opening and closing ceremonies.

The reconciliatory mood reached its peak when Moon met the sister of the North Korean leader Kim Jong-un at Cheong Wa Dae and received his invitation to visit Pyongyang.

High-level contacts between the two sides continued as Moon met Kim Yong-chol, vice chairman of North Korea’s ruling Workers’ Party Central Committee who led an eight-member delegation to the Olympic closing ceremony.

The series of high-level contacts are almost certain to lead to more reconciliatory actions to be taken by the two sides. Moon was quoted as telling Kim Yong-chol that the two sides should expand their relations broadly, to which the North Korean official responded that its leader Kim Jong-un has the same intention to move the inter-Korean ties forward.

The two Koreas already agreed when they held talks on the North’s participation in the PyeongChang Olympics that they would arrange separate talks between their military officers and high-level government officials.

In addition, the Unification Ministry in Seoul said Sunday that the Seoul government would try to take advantage of the Olympics to further improve relations with the North.

Specifically, the ministry mentioned sending a special presidential envoy to Pyongyang and promoting inter-Korean cooperation and exchanges in health care, forestry, religion, sports and culture. It also mentioned the reunion of separated families and humanitarian aid to underprivileged citizens in the North.

If all those plans go well, they will certainly contribute to the easing tensions between the two Koreas and eventually resolving the crisis involving the North’s nuclear and missile threats.

But there are two big preconditions for seeking better relations between the two Koreas: Sincerity on the part of the North and prudence on the part of the South.

North Korea is mistaken if it believes that -- without doing anything with its nuclear and missile programs -- it will be able to use improved ties with the South as a tool to tide over the ongoing international sanctions and avoid possible military action by the US.

For its part, the South should not rush to appease the North, which could sow discord with the US and augment public dissent in the South. Just look at the vehement protests of conservative oppositionists and bereaved family members of those who perished in the North Korean torpedoing of the Cheonan naval ship against the visit of Kim Yong-chol, who is suspected of having masterminded the attack in 2010 which killed 46 sailors.

All in all, a real improvement in inter-Korean relations would not come without progress in the denuclearization issue. There is no doubt that one of the first steps should be for the North to put a moratorium on its nuclear and missile tests. That also could pave the way for talks between the US and the North.